Black Swift board has 2 integrated Ethernet (10/100 Mbps) ports, but to use them you need to add a few external components. There are two ways to use them:
- Regular RJ-45 socket and transformer
- Transformerless design
Regular RJ-45 socket
Ethernet requires galvanic isolation between devices, and to provide it you have to use specialiazed transformer. Simplest way here is to use RJ-45 socket with integrated transformer (e.g. HR911105A from Hanrun Electronics, easily available on eBay):
In case you need short Ethernet connection between two modules within same device or even same mainboard, usually there's no need in galvanic isolation so you can omit transformers:
NB: transformerless design is not, repeat NOT, suitable for long-distance inter-device communication, and may damage your device(s) due to difference in ground levels and/or induced voltages!